But phone trafficking is driven largely by the massive profits made by exploiting the price difference between smartphones sold in the U.S. and overseas. Americans who agree to two-year service contracts with their cell phone company can buy the latest iPhones for about $200 -- a price subsidized by the carrier. In Hong Kong, an iPhone can be sold for as much as $2,000.

This equation helps explain why more than 1.6 million Americans were victims of smartphone theft last year and why thefts of mobile devices now make up 40 percentof all robberies in major American cities. The rising street crime is exacting a heavy toll on consumers who spend an estimated $30 billion each year replacing lost and stolen devices, according to Lookout, a San Francisco-based mobile security firm.

Story is largely about a Detroit-based fencing operation where stolen devices were exchanged for cash. So many people were lined up outside the shop they put in portable toilets.